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31  Forum 2005-2010 (read only) / Interfacing / Re: power needs for 13 arduino pro mini's + on: May 06, 2009, 11:27:35 pm
The current draw on my Arduino Pro Mini w/ATmega164 = 27mA...so clearly my original estimate was too low. I'm hoping the ATmega328 doesn't require that much more power.

Thanks again for your help.

David

32  Forum 2005-2010 (read only) / Interfacing / Re: power needs for 13 arduino pro mini's + on: May 06, 2009, 03:24:42 am
Great! That did seem pretty low, but it's what I gathered from the docs on the ATmega328, I'll test my ATmega164 in the morn to see what it draws, tho.

Thanks again for your input.

Best,
David

33  Forum 2005-2010 (read only) / Interfacing / power needs for 13 arduino pro mini's + on: May 05, 2009, 09:52:12 pm
Hi all,
I'm in the process of mapping out my power needs for a project. Here are all the components:
13 * Arduino Pro Minis (5V/16Mhz/ATmega328)
1 * bluetooth modem
1 * digital compass
77 * photocells (6/arduino) (http://www.sparkfun.com/commerce/product_info.php?products_id=9088)

Everything will run off 5V (what that is is still TBD, but certainly battery power). Modem draws ~30mA, compass ~5mA, and each arduino I'm estimating at 10mA (primarily to power the ATmega328). That's a total of ~165mA, which I could easily power with 4AA's (or step-up a couple AA's)...which is of course making me question my math here.

My question is what do each of the photocells add to the current draw, or do they it? I'm afraid I'm learning electrical engineering on the fly, and not sure how to plan for this.

Thanks in advance!

Cheers,
David

EDIT: the Arduino's will all be talking to each other via I2C, e.g. http://www.uchobby.com/index.php/2008/09/16/introduction-to-i2c
...I imagine that would also impact the current draw/arduino?
34  Forum 2005-2010 (read only) / Interfacing / Re: Arduino pro mini + bluesmirf + digital compass on: May 01, 2009, 06:46:29 pm
Thought I'd might resurrect this post!

After a few weeks of trying to get AFSoftserial to work, I gave up...horribly defeated smiley-sad And after doing more research it seems like this path wasn't a good one given the characteristics of the compass.

My work around since my last post has been 2 bluesmirf modems...one connected to an arduino pro mini, the other to the digital compass, but am now revisiting this problem, and wanted to solicit any advice. The arduino and the compass do NOT need to talk to each other...really my only goal is to have both connect to the bluesmirf modem, then pass the info along to my mac. Everything talks TTL. It just seems such a waste to have 2 modems in the same space.

Thanks in advance for any nugget of wisdom!

Best,
David

P.S. Over the past couple days I've also revisited the softSerial idea using "newSoftSerial", but still haven't had any luck.
35  Forum 2005-2010 (read only) / Interfacing / Re: Arduino pro mini + bluesmirf + digital compass on: January 19, 2009, 12:02:34 am
well...it should work, yes? I've been hacking away at this all day and can't even get the simple test code to work:

Code:
#include <AFSoftSerial.h>

AFSoftSerial mySerial =  AFSoftSerial(3, 2);

void setup()  {
  pinMode(13, OUTPUT);
  Serial.begin(9600);
  Serial.println("Goodnight moon!");
  // set the data rate for the SoftwareSerial port
  mySerial.begin(9600);
  mySerial.println("Hello, world?");
}

void loop()                     // run over and over again
{
  if (mySerial.available()) {
      Serial.print((char)mySerial.read());
  }
  if (Serial.available()) {
      mySerial.print((char)Serial.read());
  }
}

I get "Goodnight moon!" (a lovely book, btw), but no "Hello world?". This example should give me that, right? Figure if I can't get this to work, I'm not going to be a happy camper. Again, this is for an Arduino Pro Mini:
http://www.sparkfun.com/commerce/product_info.php?products_id=8991

Perhaps AFSoftSerial can't run on this board?

Any ideas on what to try next?

Thanks!!
David



36  Forum 2005-2010 (read only) / Interfacing / Arduino pro mini + bluesmirf + digital compass on: January 17, 2009, 05:30:31 pm
Hi all,

Just want to make sure I am headed down the right path here. I have my arduino pro mini working well with my bluesmirf gold. I also have my digital compass (an ocean-server OS4000T) speaking nicely to a different bluesmirf. All the data gets sent to my mac (MaxMSP) for processing...listening on two different serial ports. However everything (arduino, compass, and 2 bluesmirfs) are in the same tiny space, and therefore seems awfully silly to have 2 bluesmirfs. I've been poking around the forum all morning and it seems like connecting the compass to the arduino, and using AFSoftSerial or SoftSerial is the way to go to get data from both the compass and the arduino via a single bluesmirf. Does this sound like a logical path to head down?

Thanks!
David

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